Septic tank



W. M. PIATT SEPTIC TANK 2 Sheets-Sheet 1 1 a a i 1 a Pda/f,

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awww/g i W. M. PIATT SEPTIC TANK 2 sheets-sheet 24 Filed July 18, 15959` Patented Dec. 5, 1944 human STATES PATENT oFFicr-z SE'NK pplication .l'uly i8, 1:3032, cgi )Nm 285,179

3 Claims.

Although the material may not be essential the invention relates particularly to a septic tank which may conveniently and economically be made of pottery. Most of the parts maybe made by using as a foundation elements manufactured in the standard or usual molds employed in potteries for' pipes.

. There isprovided in general a settling chamberv into which the raw sewage may empty. Below this is a vdigestion chamber where the settled 'materials may be puried. They may be joined by inclined walls down which the settling material will fall and readily slide. Depending from the cover oi the settling chamber there may be a conduit to receive ygases formed during the digestion of the sewage. Preferably the gas receiver will be directly abovethe digestion cham- 'ber and it may have a mouth covering substantially the entire area of the entrance to the digestion chamber sothat substantially all gas formed will enter therein. Some gas may escape into the settling-chamber and may collect therein above the level of the liquid. To carry away this gas as well as tc provide for variations in amount oi air space above the level of the liquid there may be provided openings in the gas conduit as it passes through the upper part of the settling chamber.

The apparatus and its various parts may be of any suitable size and shape. For economy of manufacture, handling and installation it may be Aconvenient. to make them round but this is not essential.

stream or tiles or other disposal means, may be arranged at substantially the same level of the sewage normally in the septic tank so that normally the level of the liquid therein may be at about the level of the linal outlet opening.

IThis arrangement of the outlet, and the fact that there is thus held sewage in the outlet and more or 7less separate from the main body of the settling tank, in edect constitutes a second settling chamber. Thus although sewage liquid containing some settleable matter may enter the outlet it may be held in the outlet long enough to allow additional matter to settle from it. While its size is not essential Ait may be particu larly convenient to make the content of the outlet passage at least as large as the normal unit of incoming sewage, for instance such as may come from a ushing of the toilet bowl.

Preferably the septic tank will be iburied' below the ground level in an inconspicuous manner and may be arranged at a. suitable distance from dwellings. The 'gas outlet itself, however, may, and preferably will, be extended upward to the ground level and there be provided with a periol-ated plate through which the gas may pass and be more or less continuously dissipated into the atmosphere. The gases may be disposed of in any other suitable manner. v

Specio details are not essential to the carry ing out or embodiment of the invention. Forms of apparatus embodying the invention are illusmay pass outthis outlet.4 It will b`e understood. l

vfrom which the liquid is withdrawn, or, carried into an adjacent septic tank, or intoY a field or trated in the accompanying drawings to fully disclose the invention and not to limit it.

In the accompanying drawings Fig. l is a more or less diagrammatic transverse vertical section of two septic tanks connected into a battery. Fig. 2 is atop plan View of one form of cover for the settling chamber. Fig. 3 is a more or less diagrammatic transverse vertical section of two other'forms o'f septic tanks connected into a battery. Fig. 4 is a top plan view of another form of cover for the settling chamber.

A preferred form the invention may take is illustrated in Figs. l and 2 in which there is provided a disc or plate-like bottom it which may y have an upwardly extending rim il. .Placed in' the base ,I0 may be a pipe i2. IIihis pipe I2 may lbe heldin the bottom or the joint between it and y the bottom may be closed by'a packing i3 of cement or other`- suitable material. The various parts'of the apparatus may be packed orsimilarly .held together by means of similar packing/ I3.

" At one or more points the pipe l2 may be probe used in a b'attery as illustrated in the drawings opening or mouth of the gas conduit 35 arranged thus it will tend to collect substantially all of The apparatus and its various parts are iilustrated in the drawings as being round but the shape is not essential. Above the pipe I2 which acts as a digestion tank is a settling tank I6. This may be supported on a connecting bell or chute 36 of inverted frustro conical shape of substanf or, as shown, at aboutthe sewage level. Somewhat below the level of the inlet I9 may be provided an outlet which is illustrated as inclining upwardly and connected to a conduit 2I which may lead to and through the inlet I9 of a second septic tank, or, as illustrated at the extreme right of Fig. 1, may be connected to a pipe 22 which may lead away to an out-fall or other suitable means for disposing of the outflow from the septic tank. While vshown below the posi- -tion of the inlet the outlet part is not controlled by the position of the inlet but rather by the posi- Y tion of the retained sewage being somewhat below the sewage level.

It will be noted that the outlet pipe 20 is shown of a diameter considerably larger than the inlet pipe I9. This may be a desirable feature of the apparatus.

Closing the upper end of the settling tank I6 is a cover 23, which, as shown in Fig. 2. may be formed of one piece with a central opening 25 or may be in two parts for convenience of manipulation, as indicated in Fig. 4, each of whichparts may be provided with a screw-eye bolt 24 for ease of handling. Through the opening in the cover may be set the straight gas conductor 35. The upper end of the gas conductor may extend somewhat above the ground level and be provided with a closure plate 28 provided with suitable perforations 26' for the exit of the collected gases. Surrounding the gas conductor may be lan inset pipe 31 to retain the dirt when the conductor 35 is removed for cleaning or any other purpose. It will be noted that the conductor 35 may be withdrawn through the hole in the cover 23 without removoutlets I4 of the adjacent septic tanks.

ing the cover. Thus the inside of the septic tank may be exposed for cleaning, it being possible to thrust -a cleaning instrument clear to the bottom III `oli the digestion tank I2. The lower mouth or end of the gas conduit 35 may preferably be substantially as large in cross section as the opening through the bell 36 into the digestion chamber I2. This arrangement may leave a passage-way 30 between the outer wall of the gas conduit 35 and the tapered wall 36 so that settling portions of the sewage may readily pass down and into the digestion chamber I2. It will be noted that neither the gas conduit 35 nor any other part ofthe apparatus Y touches or impedes the tapered walls 36 so that they remain clear and unobstructed to allow a ready passage of settling matter through them into the digestion chamber I2. By having the the gas rising from the digestionchamber I2 and conduct it upward for release into the atmosphere through the platev 28. If any gas escapesthe mouth it may rise into the upper part of the settling chamber I6 above the liquid sewage. This gas, together with any gas which may be within the settling chamber itself or air displaced by incoming sewage may pass into the gas conduit 35 through openings 3I provided therein just below the cover 23.

At the left hand side of Fig. l the gas conduit 35 is shown as straight throughout its length and the'bottom opening in the bell 36 is somewhat smaller in diameter. This may be a convenience. It may be desirable, however, in some instances for purposes of manufacture, transportation or manipulation, to make the gas conduit 35a, as shown in the right hand side of Fig. 1, flared out at its bottom end 29D. The lower opening in the bell 36a may thus be made somewhat larger and the height and weight of the bell somewhat reduced.

vIn such Aan arrangement the ilared bottom 29h will not pass through the hole 25 in the top 23 in which the conductor 35a is suspended. For convenience of installation and removal, therefore, the top may be made in several pieces such as the two piece top shown inA Fig. 4, each piece being provided with one or more lifting bolts 24. In this arrangement the lining 31 may b'e omitted. l

An alternative form is shown in Figs. 3 and 4 inwhich there is provided a disc or plate-like bottom I0 which may have an upwardly extending rim Il. Placed in the base- Ill may be a pipe I2. This pipe I2 may be held in the bottom or the joint between it and the bottom may be closed by a packing I3 of cement or other suitable material. The various parts of the apparatus may be packed or similarly held together by means of similar packing I3. At one or more points the pipe I2 may be provided with an outlet opening I4 which may be closed in any suitable manner. If the tank is to be used in a-battery as illustrated in the drawings a pipe I5 may be employed to connect together the two 'I'here may be several outlets I4 and one or more may be c1osd when not being used by a disc er p1a 33.

The apparatus and its various parts are illustrated inthe drawings as being round but this shape is not essential. Above the digestion tank I2 is a settling tank I6. This may include a outh I1 of substantially the same diameter as e digestion tank I2 and inwardly flaring walls I8 are at the bottom of the walls of the settling tank I6. The'settling tank I6 as a whole in this embodiment of the invention may preferably be made larger in cross section than the digestion tank I2. In this apparatus as in that Ashown in Figs. 1 and 2 the digestion tank may -down and into the digestion chamber i2.

,tapered walls i8 are shown as integral.

. .e 2,364,472 Somewhat below the level oi' the inlet I9 may be provided an outlet 20 which is illustrated as inclining upwardhr and connected to a conduit 2| 'which may lead to and through the inlet I9 of a second septic tank or, as illustrated at the extreme right of Fig. 3, 'may be connected to a pipe 22 which may lead away to an out-fall or other suitable means for disposing of the outiiow trom the septic tank. While shown below the position of the inlet the outlet part is not con- -trolled by the position of the inlet but rather by the position of the retained sewage, being somewhat below the sewage level.

It will be noted' that the outlet pipe' 20 is shown of a diameter considerably larger than the inlet pipe I9. This may be a desirable feature' of the apparatus.

Closing the upper end of the settling tank i6 is a cover 23 which. as shown in Fig. 4. may be termed of two parts for convenience of manipulation, each oi which parts may be provided septic tanks.

Figs.y 1 or 3 or various kinds of tanks may be assembled as desired.

I t will be understood, or course, that in some instances a single tank may alone be suiiicient to take care of sewage in a single dwellingor system. Where, however, more sewage is to be handled it may be convenient to connect the tanks together in batteries of two.or more so as togive suitable capacity to the apparatus. In this instance, as illustrated in Figs. 1 and 3, there may be a connection between the tanks through the overflow outlet from one into the other and also through the connecting pipe i5 between the adjacent digestion tank portions of the various There may b`e an advantage in having the out- .let enlarged and of considerable capacity.

with a screw-eye bolt 2l for ease of handling.

The inner edgeof each of the members 23 may be out out so as to iorm an opening 25 with its upper edge bevelled slightly as at 2t to receive the depending gas conductor 2l. IThe upper end of the gas conductor may extend somewhat above the ground level and be provided with a closure plate 23 providedy with suitable periections it' for the exit ci the collected gases. The lower endoi the gas conduit 2i may preferably be tapered upwardly as at it so that the outer edges or the spreading portion 29 may be substantially as large in cross section as'the digestion chamber ii or the smaller end of the tapered wahs it. This arrangement may leave avpassage-way 3b between the outer edge of the flaring wall is and the tapered wail it so that settling portions of the sewage may readily pass Bv having the opening or mouth 2t of the gas conduit spreading it will tend to collect substantially Aall of the gas rising from the digestion chamber i2 and conduct it upward for release into the atmosphere through the plate 28. ii any gas escapes the mouth it may rise into the upper part oi the settling chamber it above the liquid sewage. This gas, together with any gasv which may be within the :settling chamber itself or air displaced by incoming sewage may pass into the gas conduit 2i through the openings 3i provided therein Just below the cover 23.

At the left hand side of Fig. 3 vthe upper portion of thesettling lchamber i6 and the lower This may be a convenience. It may be desirable, however, in some instances for purposes of manufacture, transportation or manipulation, to make l the upper portio'n Ilia, as shown in the right hand side of Fig. 3, separate 4from but suitablyA seated in or joined 'to the tapered wall portions lila, which may be made as a separate unit. Likewise at the left hand side of Fig. 3 the gas con-` duit 21 and its flaring mouth 29 'are shown as integral. They may, however, be made as separate members as indicated inthe right hand side of Fig. 3 wherefthe upper portion 21a isv indicated as made in one piece which is seated in and attached to the separate lower iiared mouth-piece 29a. v-

If a single tank is used it may be of any suit;- able frm such as illustrated at either the right or at the left of Figs.i or 3. If a battery of two or more tanks is'used they may all be made as illustrated at either the right or at the left of For instance as illustrated in Figs. l and 3 it will be understood that while there may be some iloating material on the top of the liquid sewage in the settling chamber it the outlet 2li itself, being below the surface of the sewage, may

receive substantially nothing but clear liquid.

Thus when additional sewage enters through the inlet I9 it may cause the liquid to rise in the outl'et 20 and overow passing out substantially no solid matter but merely liquid which may go into the adjacent septic tank of a battery or may go out into the spillway or the like for release from the system. It may be desirable to so proportion the outlet 2li as to give it considerable capacity so that it may be suiiicient to take vcare oi a' volume equivalent to the ordinary integer of additional sewage which may be introduced at any one time. Nevertheless the sewage will be heid in the outlet it for a short time and if there is any solid or settling material therein it may pass over or it may settle and fall down uthe -walls of the outlet tt and pass down the tapered stantially no solid matter but if solid matter does enter therein it may be held long enough to allow it to settleout.

Exact details of size, shape, proportion and relative location ofthe various parts oi the apparatus may be varied in other embodiments or the invention. e

I claim as my invention:

l. in a septic tank, a digestion chamber, a set. tling chamber above the digestion chamber and having unobstructed sloped walls between the two chambers and forming an opening therebetween, an 'inlet for the settling chamber, an outlet for the settling chamber below the inlet but inclined upwardly and extending to the sewage level vso constructed and arranged that it forms a.4 second settling chamber in the outlet, and normally retaining substantially a unit of sewage, an outlet pipe connected to the'outlet and at substantially the same level as the inlet, a cover for thetank having an aperturehtherein, a gas conductor of uniformfcross-section suspended in the aperture in the cover and-extendof the gas conductor from the iirst mentioned A settling chamber.

' 2. In a septic tankemded in the earth, a

settling chamber, a digestion chamber below the settling chamber, a gas outlet for gas from the tank extending to the surface of the earth, a cover for the settling-chamber below the surface of the earth and having an opening through which the gas outlet may be inserted and withdrawn to permit of cleaning the septic tank. and a tubular collar on the cover extending from the cover to the surface of the earth and surroundinU the gas outlet.

3. In a septic tank, a digestion chamber, a cylindrical settling chamber above the digestion chamber, an inlet for admittingunits of sewage to the settling chamber. an outlet for the settling chamber disposed substantially diametrically opposite the inlet below the sewage level but inclined upwardly and having a capacity about equal co me volume of an admitted una of sewage normally retaining substantially a unit of sewage, an outlet pipe connected to the v outlet and at substantially. the same level as the sewage, a gas conductor suspended above the digestion chamber and within the settling chamber between the inlet and the outlet and provid ing an uninterrupted channel between its walls and the walls of the settling chamber and over the digestion chamber, a cover for the settling chamber supporting the gas conductor through a hole therein, vents to atmosphere at the top of the gas conductor, and unobstructed sloped walls between the two chambers and forming an opening communicating therebetween below the aas conductor.

WILLIAM M. PIA'I'I'. 

